stepfather

1. (in the narrow sense) The husband of one's biological mother after her initial marriage to or relationship with one's biological father.Examples: "My stepfather loved me as much as he loved his own three sons. I knew how much he wanted to help me and how lacking in financial resources he was. Nothing could erase the image I gained of my real father that day: a carefree, well-to-do man who didn't really give a damn about the hopes and dreams of his firstborn son."

2. (in the broad sense) The husband of one's parent distinct from one's biological father or person with a similar relationship.Examples: "In suboptimal cases the gynaecologist takes sperm from anonymous donors. In this case the husband can only be stepfather of the child."; "Telegony or Inheritance from the Stepfather The earliest reference to telegony ( which has no connection with the son of Odysseus ) is supposed to be in 1665 but the classical case is that described in the Philosophical Transactions of[…]"